President Barack Obama on Thursday showered praise on his predecessor for “bold leadership” on an unlikely issue: AIDS treatment and prevention.

Under the banner of “compassionate conservatism,” President George W. Bush surprised and delighted AIDS activists by spending billions of dollars to fight AIDS in developing countries worldwide.

Now, nearly three years into Obama’s presidency, some of those activists say Obama has yet to create a similar legacy on the global stage.

For them, the conservative Republican often mocked as a cowboy set a standard the liberal Democrat with African ties has not matched. Bush committed to eradicating a disease that no top Republican of the 1980s or 1990s made a priority — an affliction conservatives derided in its earliest years as “gay cancer.”

“We’re hoping very much that President Obama is going to follow through on what President Bush did,” U2 frontman and AIDS activist Bono said during an appearance Wednesday on “The Daily Show.” “It was amazing. You know, people like John Kerry worked for this and Hillary Clinton, and eventually President Clinton did some extraordinary stuff renegotiating the prices of … very expensive drugs down. But George kind of knocked it out of the park.”

Other AIDS activists have been more pointed in their criticism.

“The Obama administration’s commitment to AIDS has been disappointing,” said Michael Weinstein, president and co-founder of the AIDS Healthcare Foundation. He pointed to nearly flat funding for Bush’s initiative — the President’s Emergency Plan for AIDS Relief — and a nationwide waiting list for state AIDS Drug Assistance Programs that has reached as many as 10,000 people since Obama took office. Obama on Thursday announced an additional $35 million in funding for the state programs, as well as $15 million to fund clinics.

“This administration, in general, thinks that making a speech or putting out a statement is enough to say they’ve done something, and that’s all it’s been on AIDS — everything up until now has been spin,” Weinstein said.

But not everyone is quite so harsh in their assessment of the Obama administration’s efforts.

Chris Collins, vice president and director of public policy at amfAR, the Foundation for AIDS Research, said “there is still a ways to go” in fighting HIV and AIDS, “but we’ve seen real progress under the Obama administration.”

While Collins said he had hoped for more funding for the emergency plan, he acknowledged that activists “would always like to see more money go to their cause.” And, he said, each dollar in global and domestic AIDS spending is going further than ever before as experts better understand what kind of treatments work.

While Bush focused on global AIDS with the creation of PEPFAR, senior administration officials stress that Obama has begun charting a course that both maintains and refines global efforts and also breathes new life into domestic programs.

“The president came into office wanting to reinvigorate the domestic response to AIDS, but we shouldn’t frame this as domestic or global,” a senior administration official said. “President Bush framed this as what was possible on the global front,” and the Obama administration is trying to “re-engage people in fresh ways.”

A key piece of that re-engagement is the National HIV/AIDS Strategy, rolled out in July 2010, which is aimed not just at “fighting the virus” but also at pushing “a broader effort to make life more just and equitable for the people who inhabit this Earth,” Obama said when he announced the plan’s release.

In creating that plan, Obama said Thursday, “we went back to basics: prevention, treatment and focusing our efforts where the need is greatest. And we laid out a vision where every American, regardless of age, gender, race, ethnicity, sexual orientation, gender identity or socioeconomic status, can get access to life-extending care.”

Obama’s speech at The George Washington University looked ahead to combating AIDS among a domestic population that is disproportionately composed of gay men and African-Americans.

Bush, who appeared at the event via teleconference from an AIDS hospital in Tanzania before Obama spoke, stressed the importance of helping the rest of the world and touted the success of the emergency plan he launched in 2003.

“There is nothing more effective than PEPFAR,” Bush said. “The number of people who live today as a result of PEPFAR is staggering.”

“This is something our American citizens must understand and our government must understand: There is no greater priority than living out the admonition, ‘To whom much is given, much is required,’” he said. “We’re a blessed nation in United States of America, and I believe we are required to support effective programs that save lives.”

In 2000, Bush campaigned for the White House on a platform that opposed most foreign aid, but when he reached the Oval Office, his views — at least with regard to the global AIDS epidemic — began to change. His first secretary of state, Colin Powell, urged action because the disease had become a threat to national security. Christian conservative leaders and then-Sen. Bill Frist (R-Tenn.) also began to champion the cause.

When Bush pushed Congress to support the creation of PEPFAR in 2003, his plea was about “foreign policy moralism,” former Bush speechwriter Michael Gerson later told The New York Times. “It fit a broader conception of his view of America’s purpose in the world, which included not just the liberation of other people but their treatment for disease.”

The first authorization of PEPFAR committed $15 billion to AIDS relief over five years, primarily in Africa and the Caribbean. And as Bush’s administration came to a close, he signed into law a new plan that mapped out an additional $48 billion in aid over five years.

“George Bush is a hero in this effort in terms of tackling the global epidemic,” Collins said. “He wanted to do a program that would have a major, lasting impact on the epidemic, and he did.”

The creation of PEPFAR was “sort of the most significant achievement of the Bush administration,” said Nathan Schaefer, director of public policy at Gay Men’s Health Crisis, who isn’t a big fan of the 43rd president’s work on other issues.

Yet Collins and Schaefer do not offer unqualified praise of Bush’s efforts on AIDS. They object to his focus on abstinence-only education and his avoidance of programs targeting commercial sex workers, men who have sex with men and drug users who use needles for injections.

Obama, who on Thursday called Bush’s global progress to fight AIDS one of his “greatest legacies,” also has lauded Bush’s work in the past. On World AIDS Day in 2008, as president-elect, Obama “salute[d] President Bush for his leadership in crafting a plan for AIDS relief in Africa and backing it up with funding dedicated to saving lives and preventing the spread of the disease.”

On Thursday, Obama emphasized that AIDS has become a bipartisan issue, one on which “Republicans and Democrats put their common humanity before politics.”

White House press secretary Jay Carney echoed that theme.

“The announcements that [Obama] made built on the work that President Bush did on this very important issue,” Carney said Thursday. “And I would not take the steps that he’s announcing, in terms of domestic tackling of this problem, as criticism” of Bush “but just simply the right step to take at the right time.”